Due to the increasing industrial and domestic pollution experienced in our waterways over the past few years, a sharp decline has been observed in various fish populations. With this decline has come the reevaluation of the necessity for killing and preserving specimens for classroom studies.
The current method utilized by high schools, colleges and universities to study various types of fish involves obtaining specimens from their natural habitat and placing them in a fixative such as formalin resulting in the death of the specimen. This method is necessary to point out identifying characteristics and to eliminate the difficulty often accompanying the handling of live specimens.
Prior attempts to restrain specimens in the field have proven unsuccessful due to the inability to secure the specimens for a period of time without causing substantial harm. Extensive handling often results in the death of the specimen even when returned to its natural habitat. Use of anesthesia has proven undesirable due to the effects of the anesthesia on the specimens. Securing the specimens is further hindered by the size of the specimens and the slick nature of their skin. In addition, holding of the specimens also interferes with the viewing of the overall characteristics thereof.
Although tanks have been used for restraining fish, they differ substantially from the present invention both in appearance and in function. These tanks consist of a glass plate that may be inserted into a flat-bottomed tank and then pulled forward to trap the fish against the front panel of the tank. Unlike in the present invention, external pressure is exerted on the body of the fish which creates the danger of crushing the fish. The design of the prior tanks also makes it difficult to position the fish in a restrained posture.
While preservation of the specimens allows students to better manipulate the specimens and observe the characteristics of each, such practices do nothing to help preserve the fish population. Although it is arguable that field exercises might be eliminated in favor of classroom study, most feel that the combination of the two teaching methodologies is essential to optimize instructional effectiveness. As a result each year numerous specimens are sacrificed in an attempt to educate students. Typically the specimens are discarded to make room for other specimens to be collected at a later date. This repeated process is normally justified by the fact that preserved specimens tend to fade in appearance thereby making color markings difficult to distinguish.
Therefore, the present invention presents a marked improvement in the manner in which studies of the fish population may be conducted by returning each specimen to its habitat after examination without injury.